Let G:{0,1}n{0,1}2n be a pseudorandom generator. In each of the following cases, state whether G is necessarily a pseudorandom generator also. If yes, provide a proof, if not, explain with a distinguishing strategy. (a) G(s):=G(s1sn)(sn+1s2n), where s=s1s2n{0,1}2n. That is, G(s) is obtained by applying G to the first n bits of a 2n-bit seed s and then appending the remaining seed bits to the output. (b) G(s):=G(s)(G(s)1) where s{0,1}n, denotes the bitwise-XOR and 1 denotes the integer 1 represented as a 2n-bit string